Mom's to be of 2 under 2 years old.

My son is almont 6months old and I'm 9 weeks pregnant (He will be 1, 3 weeks before my due date) What is your biggest challenge you are worried about with having 2 under 2? I'm hoping my son sleeps through the night when the little one comes (He still wakes up anywhere from 4-6 times a night 😴😴) and the thought of carrying 2 car seats around at times... at least it will be a good workout right? We won't have to do much to get the baby weight off this time haha...